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Elac Reference UCR52 Review (Center Speaker)

thewas

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Strangely vertical directivity looks better even though it audibly is not as significant
Not so strange as vertically the all drivers are aligned, the reason why standing pseudo-D'Appolitos usually having smoother directivity horizontally than vertically, although it must also be said here the crossover frequencies of the woofers are much lower and could fulfil the Appolito requirement, but we don't know the total acoustic slopes and shapes which could be compromised.
 

abdo123

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Not so strange as vertically the all drivers are aligned, the reason why standing pseudo-D'Appolitos usually having smoother directivity horizontally than vertically, although it must also be said here the crossover frequencies of the woofers are much lower and could fulfil the Appolito requirement, but we don't know the total acoustic slopes and shapes which could be compromised.
I'm pretty sure you mean they're horizontally aligned, right?
 

Helicopter

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Thanks Amir.

Strange so many center channels use small drivers in an MTM configuration with lousy implementation. Sometimes I wonder if Harman is the only company that realizes this is the most important channel. This Elac is not even close to fit for running with the excellent DBR62. Shame.

I would like to see some of the 5+ driver center channels reviewed, including in-wall or on-wall designs from Harman group and Focal.
 

Transmaniacon

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One important question in the minds of many audio lovers that has not been assessed here yet is whether bi-amping makes any difference.

Center speakers like this are mostly used with AVRs that have too many amps for most users and thus give the option to bi-amp.

Bi-amping can potentially be assessed for the impact on:

1. Distortion levels
2. SPL at the same AVR volume
3. Frequency response

If there is time and interest to perform such analysis on this or any other speaker supporting bi-amping this would be super appreciated!
AVRs typically support passive biamping which doesn’t do anything. You are still sending power through the speakers crossover and not gaining anything.

Active biamping with internal crossover disabled and an external crossover utilized is the only way to see appreciable results but this is much more advanced and not something a typical AVR supports.
 

abdo123

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I'm wondering whether in its intended application for home theater, would AVRs and room correction address these issues with their auto EQ?

the directivity error at 6-7 KHz is quiet severe, and the directivity of the individual drivers is not that great either as the resonances are severe on-axis but not so severe off-axis.

I do not think EQ can help that much. without sacrificing either the on-axis response or the off-axis response.

Edit: What you should be looking for is something like the DIYSG-HTM V2.0, there is an abundance of resonances but the sensitivity is great and the directivity is near sublime.

CEA2034%20--%20DIYSG%20HTM-12%20v2.png
 
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beagleman

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Sur

Surly Amir isn’t somehow always getting duds? Everything he reviews seems to have it in some considerable quantity.


Unlikely, but a loose screw has plagued a FEW of my new speakers.

Running tones, I would just touch each screw with screwdriver and then turn, and it would go from loud buzzing to gone....Just a guess.
 

joentell

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Thanks for this @amirm. It helps clarify something for me personally.

When I reviewed the entire ELAC Uni-Fi Reference line, I noticed that the UCR52 center channel had that response that you showed, but the UBR62 bookshelf and the floorstander did not have the same odd response. I figured it was an issue with mine since I received early pre-production versions.

Here's my overlaid in-room near-field UCR52 measurement in purple over your PIR adjusted to match your scale.
PIR vs In-Room.jpg



Here's the same graph overlaid over your near-field response.
Near in Purple.jpg



What I found odd was the ELAC UBR62 bookshelf (red) and the ELAC UFR52 floorstander (green) didn't have the same top-end response as the ELAC UCR52 center (purple).
All Three.jpg

Hope this info is helpful to someone.
 

Chromatischism

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Hate to keep defending stuff, but remove the resonance issue, and the actual frequency response is still fairly within + or - about 3db or so.

Not TRULY horrible, but just not good for the price...
Amir said he had a hard time hearing the resonance at normal listening (86 dB) levels, which is why I don't think it's broken. Clearly this speaker isn't meant for high SPL, and personally I want a speaker that never flinches even during those rare times when output spikes that high (an action movie, for example).
 

pseudoid

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Thanks Amir....
I would like to see some of the 5+ driver center channels reviewed, including in-wall or on-wall designs from Harman group and Focal.
I am wondering if the L/R ports (their placement/design) are partially responsible... I would not dare ask @amirm to experiment with some lipstick (errrr... stuffing) for this cute piggie's pie/poop holes...
@Helicopter >> Would a smallish Polk Reserve R350 Center (unported LCR @four 4"woofers + 1" tweeter) satisfy your wish?
He has such a unit on loan...
 
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Pulkass

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This is a review and detailed measurements of the Elac Unifi Reference UCR52 center home theater speaker. It was kindly purchased new by a member and drop shipped to me. The UCR52 costs US $700.

The UCR52 enclosure is nice looking but I don't the wisdom of having highly reflective, chrome polished rings around a speaker in a theater application:

View attachment 158028

Even during music listening I found the reflective edges eye catching in the wrong way. There is a magnetic grill so you can hide them.

This is a three-way speaker with dual woofer and a mid-range+tweeter coaxial/coincidental driver. 3-way is my preference for center speaker to avoid directivity dips with so called MTM 2-way speakers.

Back panel sports very nice looking and feeling binding posts:

View attachment 158029

Measurements that you are about to see were performed using the Klippel Near-field Scanner (NFS). This is a robotic measurement system that analyzes the speaker all around and is able (using advanced mathematics and dual scan) to subtract room reflections (so where I measure it doesn't matter). It also measures the speaker at close distance ("near-field") which sharply reduces the impact of room noise. Using computational acoustics, far-field response is computed and that is what I present. Both of these factors enable testing in ordinary rooms yet results that can be more accurate than an anechoic chamber.

I performed over 1000 measurement which resulted in error rate of about 1%.

Reference axis is approximately the center of the tweeter. Grill was not used.

Unifi Reference UCR52 Measurements
Acoustic measurements can be grouped in a way that can be perceptually analyzed to determine how good a speaker is and how it can be used in a room. This so called spinorama shows us just about everything we need to know about the speaker with respect to tonality and some flaws:

View attachment 158031

Wow, I must say, I did not remotely expect to see such a rough frequency response. It has both macro and micro level variations all over the place. Near-field measurements of each sound radiating elements explains some of this:

View attachment 158033

Notice the very uneven response of the coaxial driver. We also have a port/cabinet resonance around 1 kHz. Let me jump ahead and show you distortion response:

View attachment 158034

View attachment 158035

When I was measuring the speaker I distinctly heard a sharp sound coming part way through the sweep. Note that I wear strong hearing protection so normally don't hear problems with speakers unless they are very severe. And this was. I got close to the speaker and put my hand on the cabinet. Right when I heard the output of norm, higher pitch sound, I would also feel the cabinet resonating. This occurred with the 96 dBSPL sweep. So I looked and saw that large peak between 500 Hz and 1 kHz. So I created a sweep that only excited that range of frequencies and I could hear the tone again.

Last time I reported a resonance like this it too was an a Elac speaker, the Unifi 2.0. There was a lot of doubt then as to whether this was really there so I decided to make a recording of the sweep. I used my phone to see if it can capture it and it did. See the sample zip file. Here is the amplitude evenelop:

View attachment 158036

You can clearly see the amplification of the tone before the sweep ends. If you play the audio file in an audio workstation software, you can easily hear the zing at the end in sync with that peak.

I tested this at 86 dBSPL and it was harder to hear it there.

Anyway, back to our measurements, here is our early window reflections:


View attachment 158037

Response is thankfully smoothed out due to a number of reflections being summed but we still have a shelving of upper bass and midrange. This results in the same issue in predicted in-room frequency response:

View attachment 158039

Horizontal beamwidth is pretty uneven but fairly wide in mid-frequencies:

View attachment 158040

Same is seen in the colored contoured version:

View attachment 158041

There are sharp edges around the metal the surrounds the coaxial driver. So I wonder it is causing some diffractions here that we see at the edge of our envelop.

Strangely vertical directivity looks better even though it audibly is not as significant:

View attachment 158042

I guess it doesn't have two woofers flanking it like the horizontal plane does.

The three snapshots I take land in the sweet spot of the speaker so show good response:

View attachment 158043

Impedance dips to 5 ohm so make sure you have a decent amplifier to drive this speaker:

View attachment 158044

Note that our resonance shows up clearly here as well in both phase and amplitude response.

Elac Uni-fi Reference UCR52 Listening Tests and EQ
Having seen the measurements in advance, I expected poor sound but did not get it. What was there was quite pleasant with very good dynamic ability. Wondering if I had lost all ability to subjectively assess speakers, I went ahead and put in a couple of filters to deal with that step up response between 200 and 1000 Hz:

View attachment 158045

At first, the difference was subtle but then I listened for 15 minutes and then turned off the EQ. Wow, so much muddier and a bit tubbier without EQ. Vocals came forward now which is what you want in a center speaker.

Conclusions
I know the word "reference" has been bastardized in audio to almost mean nothing but still, I expected more, far more from Elac and Andrew Jones. What were they thinking? How could they produce such a technically flawed speaker? When I can hear a resonance with hearing protection in a simple log sweep, surely they could too. Do they only play at low and modest levels and don't hear such things? If so, what is up with the uneven frequency response? Is this all tuned by ear? Why is it so uneven anyway? Was this pushed out the door before being finished? Lot of questions.

Thankfully or not, in a battle of subjectivity vs objectivity, with a bit of EQ it performs a lot better than it should. Dual woofers give it high SPL playback ability which is an effective way to get on my good side. :) This is super important in home theater applications were the center speaker carries most of the burden as it has to show all that is seen on screen.

On the resonance, I could not get a clear case of it showing up. Either I was not playing loud enough or that the tone was getting added to other parts of the music and it was not as obvious as it was in Uni-fi 2.0.

Anyway, I think technically the ELAC Uni-fi Reference UCR52 is a failure and I can't recommend it. Subjectively, with some EQ it can be made to sound good. You get to decide which side of me you want to believe. :)

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As always, questions, comments, recommendations, etc. are welcome.

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Thanks For being so clear and true. There is really some atrocious hi fi stuff out there !!!! And expensive.
 

Shazb0t

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It looks feasible that an argument could be made that the original Uni-Fi line is the best of their coaxial series. It's weird of Elac to have gone through two further iterations only to have ended up with this.
 

williamwally

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Someone recently made a thread asking why more speakers aren't coaxial. I feel like this speaker is a perfect example of why most aren't.
 
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